Indicator system



June 10, 1930. c. L. DAVIS INDICATOR SYSTEM Filed Feb. '12, 1930 IN V ENTOR.

ATTORNEY Patented June 10, 1930 UNITED STATES PATENT: OFFICE;

onnsrnn. L. DAVIS, or KEOKUK, IOWA, AssIeNoR TO wmru) mnro, me, or mewYORK, ".N'. Y A. CORPORATION OF DELAWARE INDICATOR SYSTEM Originalapplication filed March 7, 1929; Serial Ne. 345,167. Divided and thisapplication filed 12, 1930. Serial No. 427,836.

' My invention relates broadly 'to high frequency signaling systems andmore particularly to a frequency adjusting apparatus employed insignaling transmitters and re- 5 ceivers. 4 This application is adivision of my application Serial No. 345,161 for Frequency adjustingmeans for high frequency signaling system, filed March 7, 192

vid means for accurately and selectively adjusting high frequencyapparatus to a predetermined position for precision operation.

Another object ofmy invention is to provide a form -of mounting for amagnifying system for observing the calibrations on an indicating drumor dial in high frequencysignal transmission and receiving apparatus.

' A still further object of-my invention is to provide a construction oflens carrier for facilitating the focus and removal'of a magnifying lensin a high frequency adjusting apparatus. Y j v I Other and furtherobjects of my invention reside in the method of mounting an enlargedlens with respect to a frequenc adjusting mechanism as set forth morelly in the specifications hereinafter following by reference to theaccompany drawings, in which:

Figure 1 is a front elevation showing the observation device of myinvent-ion in position with respect to a calibrated drum in a frequencycontrol apparatus Fig. 2 is a crosssectionalview taken through the lenscarrier and mounting therefor on line 22 of Fig. 1; Fig. 3 is a lateralcross-sectional view through the lens carrier and mounting on line 3-3of Fig. 2; and Fig. 4 is a cross-sectional view through the lenshousing-and side elevational view of the lens carrier about to bepositioned within the lens mounting adjacentthe frequenc controlapparatus. 1.

In i h frequency signaling stems including 0th transmitters andreceivers, some form of frequency adjustingi means is employed.Associated with suc means is provided a dial which is calibrated infrequency or merely in arbitrary numbers from which the frequency may bedetermined. It is dilficult to provide an accurately calibrated disk ordial from which the frequency may be as-' certained without designing adial of large to properly and accurately determine the calibratlonindicatedat a particular adj ustment, In my improvements'in highfrequency sig-v naling systems, I provide certain features 1 One oftheobjects of my invention is to pro-,

whereby the frequency adjustment of the high frequency apparatus may beaccurately and readily determined and whereby the fre-' ries laterallyextending calibrations thereon which are extremel close together,enabling the shaft 1 to .be adjusted through small angular distancesrepresented by a multiplicity of calibrations. rear of the instrumentpanel 3 and'extends over the periphery of the calibrated drum 5 througha relatively large arc. The end of the hood 7 is suitably shaped asrepresented at 9 to conform with the periphery of the drum 5. The flange10 on the hood 7 is secured to the end of the instrument panel 3 bysuitable screws or other fastening means in such manner that theinternal bore of the hood 7 registers with the aperture 11' in theinstrument panel 3. An enlarging, lens 2 is mounted in an annular frame12-having a plurality of spring fingers 6 extending therefrom andfrictional- 11y engaging the interior walls of the hood 7 1e enlarginlens 2 is so mounted in the carrier 12 that 1t is aligned with thecalibrations on the drum 5 and serves to enlarge the-divisions on thecalibrated surface 'of the drum 5 from the condition illustrated in Fig-February A hood 7 is secured to the tions on the drum to enable accurateobservations to be made of the movement of the'drum and therebypermitting more accurate settings of the drum for a particular frequencyposition than has heretofore been possible.

The advantages of the 'improvementsin high frequency signaling systemsof my invention are numerous. In the employment of extremely highfrequency electrical energy, it is essential that the frequencyadjusting means be accurately calibrated. The interpolation between twonumbers or degrees of the'calibration is difficult and accuratedetermination of the frequency adjustment from the calibrated indicatingmeans is nearly impossible. This 'is' due to the inaccuracy ofcalibration, mechanical features of construction or minuteness of thecalibrated portion. Enlarging the calibrated drum or dial by enlargingits physical dimensions has previously been referred to and obviously isnot a desirable feature. By employing an enlarging lens in the mannerdescribed, the actual physical enlargement of the calibrated portionwith its accompanying disadvantages is avoided, while the dial or drumis optically enlarged to the observer. The calibration may be so smallas not to be visible with the eye alone. The features ofmicro-mechanical adjusting means whereby effort is'made to secureapproximateindb cation is far inferior to the foregoing improvements ofmy invention. Physical expansion of the dial or drum due to an in-vcrease in temperature is greatly reduced'by employing a small andaccurately calibrated dial or drum.

While I have desgribed my invention in a preferred embodiment, I desirethat it be understood that modifications may be made and that nolimitations upon my invention are intended other than are imposed by thesco e of the appended claims. I

l 'hat I claim as new and desire to secure by Letters Patent of theUnited States is as follows:

1. An indicator apparatus for frequency control systems comprisin incombination with a calibrated drum, an instrument panel, a hoodextending from the rear of said instrument anel and envelo ing a portionof the perip eral surface of said calibrated drum, and a lens insertablethrough the instrument panel to a position within said hood formagmfying the calibrations on said calibrated drum. r

2. An indicator apparatus comprising a rotary member having calibrationsthereon, said rotary member bein disposed behind an instrument panel, aho extending between said rotary member and said instrument panel, andan enlarging lens insertable.

through said instrument panel to a osition within said hood for viewingcali rations on said rotary member,

toward or away from said rotary member,

and an enlarging lens mounted in said lens carrier for enabling thecalibrations on said rotary indicator to be observed in magnifiedproportions through said instrument panel.

4. In an indicator apparatus, a rotatable member positioned behind, aninstrument panel and having calibrations thereon indieating angularmovements thereof, a hood extending between the instrument panel andsaid rotatable member and embracing a calibrated portion of saidrotatable member, a lens carrier insertable through the instrument paneland adjustable to selected positions within said hood, and an enlarginglens mounted in said lens carrier for observing the calibrations onsaidrotatable member in enlarged proportions. I

5. In an indicator apparatus, a rotatable meniber having calibrationsthereon, said rotatable member being movable behind an instrument panel,a hood extending between said instrument panel and enveloping acalibrated portion of said rotatable member, a lens carrierinsertablethrough the instrument panel to a position within said hood, said lenscarrier having a plurality of resilient fin ers extending longitudinallytherefrom for Erictionally gripping the interior walls of said hood, andan enlarging lens mounted in said lens carrier for enabling thecalibrations on said rotatable member to be viewed in magnifiedproportions through the instrument pane I In testimony whereof I a-fiixmy signature.

CHESTER L. DAVIS.

